Cylinder fin construction



Dec. l5, 1936. R. CHILTON ET A1.

CYLINDER FIN CONSTRUCTION Filed March 17. 1936 INVENToR Kor/a /m (f/fof? v ATTORNEY Patented Dec. 15, 1936 UNirEo s'rA'rEs `Grubman rinn coNs'rnUc'rroN Roland Chilton, Ridgewood, and Rudolph lF. Gagg, Fair Lawn, N. d., assignors to The llt/eed Propeller Co., Inc., a corporation or New York Application March 17, 1936, Serial No. 63,289

6 Claims.

This invention relates to air-cooled engine cylinder barrels and comprises an improved nning means especially suited for cylinder barrels having enlarged diameter end portions.

Objects of the invention are to obtain higher,`

Fig. -1 is a longitudinal section through a cylinder barrel incorporating the fins of this invention; and Fig 2 is a sectional plan view on the line 2-2 of Fig. 1.

In the drawing, I0 designates an air-cooled cylinder barrel of high strength material suchv as steel, having the usual hold-down flange I2 and the usual threads I4 onto which the cylinder head I6 is screwed and shrunk in the usual way.

As usual, in order to save weight, the exterior diameter of the cylinder between the threads I4 and the flange I2 is smallerA than the outside diameter at the threads which accordingly precludes the application of endless rings for direct contact with the cylinder barrel surface. However, application of endless rings is desirable, instead of conventionally machining the ns from the cylinder barrel itself, to gain in lightness, heat conduction and low cost.

according to the provisions of this invention, a ysplit sleeve or jacket I8 having a parting I9 issprung on to envelop the part of the barrel tobe nned. The thickness of the sleeve is such that its outside diameter is as great as that of threads I4 while the sleeve is made of light, high conductivity material such as aluminum, whereby considerable weight is saved as compared to the case where the steel barrel itself is increased in thickness to permit of assembly of the iins past the screw-threaded portion. Fins 20, preferably also of aluminum, have enlarged bases as shown at 2l and are assembled by slipping them over the'threads I4 and by shrinking onto the outer sleeve I8 from elevated temperatures. whereby, upon cooling, high `contact pressures, giving good thermal conductivity atv the joints, are obtained, between the cylinder and sleeve and between the sleeve and iin rings.

' understanding While we have described our invention .in detail in its present preferred embodiment, it will be obvious to those skilled in the art, after our invention, that various changes and modications may be made therein 5 without departing from the spirit or scope thereof. We aim in the appended claims to cover all such modications and changes.

What is claimed is:

1. The combination with a cylinder barrel hav- 10 ing a reduced external diameter intermediate its ends, of a plurality of endless iins having a bore sufficiently large to pass one'said end, and a split sleeve closely enveloping said barrel and onto which said iins are shrunk. g5

2. The combination with a cylinder barrel having projecting screw threads adapted to secure a cylinder head, of a split sleeve adapted to be sprung over said threads and having equivalent outer diameter thereto, and endless iin 20 rings shrunk upon said sleeve.

3. The combination with a cylinder barrel, having projecting cylinder head securing threads, of a split sleeve encircling said barrel, and iin rings shrunk upon said sleeve. 25

4. The combination with a cylinder barrel, having projecting cylinder head securing threads, of a split sleeve encircling said barrel, and fin rings shrunk upon said sleeve, said sleeve and fins being of lighter and thermally morecon- 30 ductive material than said barrel.

5. The combination with a cylinder barrel, having projecting cylinder head securing threads, of a split sleeve encircling said barrel, and iin rings shrunk upon said sleeve, said barrel being 35 of stronger and heavier material than said ns and sleeve.

6. The combination with a tubular member having a central cylindrical portion of less diameter than the end portions, of a sheet of light material wrapped around said central portion, said sheet'having a thickness at least eq'ual to the difference in radii between saidv central portion and one, of said end portions, and a plurality of n rings having an internal di- 45 ameter at least equal to that of said end portion, adapted for tting engagement around said sheet.

ROLAND CHILTON. RUDOLPH F. GAGG. 50 

